Medical marijuana dispensaries are limited to certain areas of The City under a 2005 law. The opening of three clubs in one Outer Mission neighborhood this year got the attention of Supervisor John Avalos.

Medical marijuana dispensaries could soon open in more than just a few San Francisco neighborhoods after the clustering of these businesses stoked political tensions and prompted calls for rule changes before the end of the year.

The proposed review of the 2005 land-use controls for dispensaries was somewhat forced upon city officials earlier this year. Supervisor John Avalos sought to prevent a clustering effect of shops after three were permitted to open in close proximity to one another — two on one block — in the Outer Mission neighborhood he represents.

Medical marijuana advocates slammed that proposal for squeezing the already limited areas where such businesses can open. They also feared it would lead to similar ad hoc limits on the allowable areas for pot clubs, which are estimated to comprise 10 percent of The City's land mass. The proposal is now on hold.

However, Avalos introduced legislation last week that would require the Planning Commission to review the 2005 medical marijuana law and provide recommendations for changes to the Board of Supervisors by Jan. 1. The review would include analysis of "impacts on the public health, safety and welfare of expanding the areas" where dispensaries can open and the impact of existing rules on patient access.

Avalos said the flawed 2005 law has led to unfair zoning.

"They should be situated throughout The City, not just in certain neighborhoods," he said.

The review comes at a particularly volatile time for the medical marijuana movement as federal authorities continue to target California dispensaries even though medical marijuana has been legal under state law for more than 15 years. There are more than 20 permitted dispensaries in San Francisco, and eight have been shuttered by federal authorities since late 2011.

Shona Gochenaur, a medical marijuana activist and executive director of low-income patient collective Axis of Love, was among those who blasted Avalos' Outer Mission proposal. But she welcomed and praised his proposal for the broad review.

As it stands, she said, there are access issues for patients living in neighborhoods such as Bayview-Hunters Point and the Sunset, where there are no dispensaries.

Gochenaur said she expects similar political fighting and neighborhood opposition, as in 2005, to any dispensary changes, but noted that public acceptance of medical marijuana has increased and the track record of dispensaries operating under the established regulatory system has proven critics wrong.